Hydrogen sulfide (H 2 S) and methylglyoxal (MG) were supposed to be novel signaling molecules in plants. However, whether interplay between H 2 S and MG can initiate thermotolerance in maize seedlings and in relation to metabolism of reactive oxygen species (ROS) and osmolytes is little known. In this study, watering with MG and NaHS (H 2 S donor) alone or in combination elevated survival and tissue vigor of maize seedlings under heat stress and coped with an increase in the biomembrane injury (as indicated in membrane lipid peroxidation and electrolyte leakage). The above-mentioned effects were separately weakened by MG scavengers (N-acetyl cysteine: NAC; aminoguanidine: AG) and H 2 S inhibitor (DL-propargylglycine, PAG) and scavenger (hypotaurine, HT). These suggested that the interplay between H 2 S and MG initiated the thermotolerance in maize seedlings. The further data indicated that, under non-heat stress and heat stress conditions, MG and NaHS alone or in combination modulated ROS metabolism by regulating the activities of antioxidant enzymes (catalase, ascorbate peroxidase, guaiacol peroxidase, glutathione reductase, monodehydroascorbate reductase, and dehydroascorbate reductase) and the contents of non-enzymatic antioxidants (ascorbic acid, glutathione, flavonoids, and carotenoids) in maize seedlings. In addition, MG and NaHS alone or in combination also separately modulated the metabolism of osmolytes (proline, trehalose, glycine betaine, and total soluble sugar), H 2 S (L-cysteine desulfhydrase and O-acetylserine (thione) lyase), and MG (glyoxalase I, glyoxalase II, and MG reductase). These physiological effects also were separately impaired by NAC, AG, PAG, and HT. The current data illustrated that the interplay between H 2 S and MG initiated the thermotolerance in maize seedlings by modulating ROS, osmolyte, H 2 S, and MG metabolism.

中文翻译：

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硫化氢和甲基乙二醛之间的相互作用通过调节活性氧化物质和渗透物代谢启动玉米幼苗的耐热性

硫化氢 (H 2 S) 和甲基乙二醛 (MG) 被认为是植物中的新型信号分子。然而，H 2 S 和MG 之间的相互作用是否可以引发玉米幼苗的耐热性以及与活性氧(ROS) 和渗透物代谢的关系鲜为人知。在这项研究中，单独或联合使用 MG 和 NaHS（H 2 S 供体）浇水可提高热应激下玉米幼苗的存活率和组织活力，并应对生物膜损伤的增加（如膜脂质过氧化和电解质泄漏所示） . MG清除剂（N-乙酰半胱氨酸：NAC；氨基胍：AG）和H 2 S抑制剂（DL-炔丙基甘氨酸，PAG）和清除剂（次牛磺酸，HT）分别削弱了上述作用。这些表明H 2 S 和MG 之间的相互作用引发了玉米幼苗的耐热性。进一步的数据表明，在非热应激和热应激条件下，MG 和 NaHS 单独或联合通过调节抗氧化酶（过氧化氢酶、抗坏血酸过氧化物酶、愈创木酚过氧化物酶、谷胱甘肽还原酶、单脱氢抗坏血酸还原酶和脱氢抗坏血酸还原酶）和玉米幼苗中非酶抗氧化剂（抗坏血酸、谷胱甘肽、类黄酮和类胡萝卜素）的含量。此外，MG 和 NaHS 单独或组合还分别调节渗透物（脯氨酸、海藻糖、甘氨酸甜菜碱和总可溶性糖）、H 2 S（L-半胱氨酸脱硫酶和 O-乙酰丝氨酸（硫酮）裂解酶）和MG（乙二醛酶 I、乙二醛酶 II 和 MG 还原酶）。这些生理作用也分别受到 NAC、AG、PAG 和 HT 的损害。目前的数据表明，H 2 S 和MG 之间的相互作用通过调节ROS、渗透物、H 2 S 和MG 代谢启动了玉米幼苗的耐热性。